Functional MBS impact modifiers for use in engineering resins

ABSTRACT

The invention relates to a methylmethacrylate-butadiene-styrene (MBS) core/shell polymer impact modifier containing functionalization in the shell. The functionalized MBS is useful as an impact modifier in engineering resins, and especially in blends of engineering resins, particularly where the blend contains both functional and non-functional resins. One specific engineering resin blend having excellent low temperature impact performance is a polycarbonate (PC)/polyethylene terephthalate (PET) blend with the functional MBS of the present invention.

FIELD OF THE INVENTION

The invention relates to a methylmethacrylate-butadiene-styrene (MBS)core/shell polymer impact modifier containing functionalization in theshell. The functionalized MBS is useful as an impact modifier inengineering resins, and especially in blends of engineering resins,particularly where the blend contains both functional and non-functionalresins. One specific engineering resin blend having excellent lowtemperature impact performance is a polycarbonate (PC)/polyethyleneterephthalate (PET) blend with the functional MBS of the presentinvention.

BACKGROUND OF THE INVENTION

Synthetic resins are widely used as engineering plastics in a variety ofend-uses, such as building materials and automobile parts. Theengineering resins have good physical and chemical resistance, and arelow cost. A disadvantage of some engineering resins is that they havepoor impact strength. Poor impact strength of these materials may beovercome by blending impact modifiers with the resins.

Impact modifiers generally consist of low-Tg, elastomeric polymers.Unfortunately the low-Tg polymer particles are typically difficult tohandle. They are tacky and tend to stick together (blockiness), formingclumps or agglomerates during processing and storage. The agglomeratesmay be difficult to separate and disperse into the engineering polymermatrix, leading to a less than optimal modification of the plastic.

Core shell impact modifiers typically have rigid high T_(g) polymers intheir outmost shell at levels sufficient to cover the elastomericcomponents. Such impact modifiers have good anti-blocking properties andare easy to handle. They can also be spray-dried or coagulated.

Hydroxy alkyl (meth)acrylate monomers have been incorporated into theshell of a core-shell modifier to improve compatibilization of the shellwith the matrix polymer. The use of hydroxy-functional monomers in theshell has been described in U.S. Pat. Nos. 5,321,056 and 5,409,967.

JP 54-48850 describes the use of polymers made from hydroxyl-functionalmonomers for use as impact modifiers.

U.S. Pat. No. 6,130,290 describes a core-shell particle having atwo-part shell. The outer shell contains a hydroxy alkyl (meth)acrylatecopolymer, while the inner shell does not.

U.S. Pat. No. 7,195,820 describes a core-shell polymer impact modifierwith hydrophilic monomer units in the shell. The purpose of thehydrophilic shell monomers units was to resist migration of the shellpolymer into the core—thus reducing the amount of polymer shell neededfor complete coverage of the core. These core-shell impact modifierswere considered useful in many different polymer matrixes.

Polymer matrixes consisting of blends of functional polymers withnon-functional materials present a unique challenge for impactmodification. Conventional core-shell impact modifiers withnon-functional shells tend to migrate toward the non-functional parts ofthe blend. This decreases the effectiveness of the impact modifier onthe functional polymer.

In “Functional MBS Impact Modifiers for PC/PBT Alloy” by William T. W.Tseng, and J. S. Lee, Journal of Applied Polymer Science, Vol. 76,1280-1282 (2000) the use of a functionalized MBS in a PC/PBT isexplored. A PC/PET blend was not described. Applicants have found a muchgreater synergy for a functionalized MBS in a PC/PET alloy, than in aPC/PBT alloy.

Surprisingly it has been found that the impact modification propertiesof functional and non-functional resin alloys can be improved by usingan impact modifier having a functionalized shell. One system showing anespecially large impact improvement from the functional MBS impactmodified is a polycarbonate/polyethylene terephthalate alloy.

While not being bound by any particular theory, it is believed that thefunctionalization in the particle shell associates with thefunctionalized polymer in the matrix, thus preventing migration of muchof the core-shell impact modifier into the non-functionalized portionsof the matrix, and providing localized dispersion. In a PET blend, thehydroxyl functionality on the PET reacts with the functional group onthe functionalized MBS, anchoring much of the MBS in the brittle PETphase. Additionally, the use of a functionalized shell decreases themigration of shell monomer into the core during polymerization of thecore-shell polymer, providing better shell coverage.

SUMMARY OF THE INVENTION

The invention relates to an impact modified polymer alloy compositioncomprising:

-   -   a) a functional polymer    -   b) and at least one non-functional polymer selected from the        group consisting of alkyl (meth)acrylate polymers and        copolymers, acrylonitrile/butadiene/styrene terpolymers (ABS),        acrylonitrile/styrene/acrylate copolymers, polycarbonates,        methacrylate/butadiene/styrene copolymers, polystyrene,        acrylonitrile/acrylate copolymers, acrylonitrile/methyl        methacrylate copolymers, polyolefins, poly(vinyl chloride), a        homopolymer of a vinylidene halide, and alloys thereof; and    -   c) functional core-shell impact modifier, wherein the outer-most        shell comprises    -   from 0.5 to 30 weight percent, based on the shell polymer, of        functional groups.

DETAILED DESCRIPTION OF THE INVENTION

By “core”, as used herein, is meant the outermost elastomeric layer andall stages or layers inside the outermost elastomeric polymer stage. Thecore may be a single elastomeric phase, or may consist of multiplephases or layers of polymer. The non-elastomeric and elastomericpolymers in the core may be the same or different from other polymers inthe core-shell structure. The core makes up at least 50 percent byweight of the core-shell polymer, preferably at least 70 percent, andmore preferably from 75 to 95 percent by weight.

By “polymers” and “resins”, as used herein, is meant homopolymers andcopolymers—with copolymers including polymers formed from two or moredifferent monomers, such as terpolymers, etc. The copolymer may berandom, block, graft, or tapered, and may have any architecture, such asbranched, star, or comb polymers.

By “elastomeric” and “elastomer”, as used herein, is meant any polymeror copolymer having a glass transition temperature (Tg) of less than 25°C. Preferably the elastomeric polymer has a Tg of from −120 to 0° C.Most preferably the elastomeric polymer has a Tg of from −90 to −10° C.

By “shell”, as used herein, is meant all the layers outside of theoutermost elastomeric layer of the core-shell polymer. In cases wherethe shell consists of multiple layers, the outermost shell is the layeron the outside of the core-shell particle—exposed to the environment.

The core, as defined above, includes all layers of the multi-stageparticle from the outermost elastomeric layer inward. The core may be asingle elastomeric stage, a hard layer surrounded by an elastomericlayer, or any number of elastomeric and hard layers wherein the outerlayer is an elastomeric polymer. The core could also be made of a matrixof hard and elastomeric materials, having an elastomeric layer as theoutermost layer. At least 30 percent of the core is made of elastomericpolymer(s). Preferably at least 40 percent of the core is elastomericpolymer. Most preferably at least 50 percent of the core is elastomericpolymer.

Examples of elastomeric polymers that could be present in the coreinclude, but are not limited to, polybutadiene, butadiene-styrenecopolymers, methacrylate-butadiene-styrene terpolymers, polyisoprene,C₂-C₁₈ acrylic polymers, acrylonitrile copolymers, siloxanes or siliconcontaining elastomers.

In one embodiment, the elastomer is a styrene/butadiene copolymer. Inanother embodiment the elastomer is an acrylate/butadiene copolymer. Inother embodiments the elastomer is an acrylate polymer or copolymer or ahomopolymer of butadiene.

The polymer cores are formed by free-radical emulsion polymerization bymeans known in the art. Where the core contains more than one layer, themultiplayer core may be synthesized by successive free radical emulsionpolymerization, as known in the art.

The shell of the present invention is composed of one or more layers ofhard polymers. By hard polymer it is meant a polymer having a Tg ofgreater than 25° C., preferably in the range of from 40 to 150° C., andmost preferably in the range of from 60 to 140° C. The outermost shelllayer contains from 0.5 to 30 weight percent, preferably 1 to 20 weightpercent, of functional units, either as a blend of functional andnon-functional polymers, or as least one copolymer formed from at leastone non-functional monomer and at least one functional monomer.

By “functional shell polymer”, as used herein, means either a blend offunctional and non-functional polymers, or at least one copolymercontaining one or more different functional groups, either in thecopolymer backbone, as pendant groups, or both. The functionalizedcopolymer may be formed in several different ways, as known in the art.These include copolymerization (random or block) of one or morefunctional monomers with non-functional monomers, grafting, andpost-polymerization functionalization of a polymer, or a mixturethereof.

Non-functional ethylenically unsaturated monomers useful in forming theshell polymer include, but are not limited to, styrene,(meth)acrylonitrile, ethyl acrylate, propyl acrylate, butyl acrylate,methyl methacrylate, divinyl benzene, acrylonitrile, and mixturesthereof.

Functional monomers useful as comonomers to add functionality to thecopolymer include, but are not limited to, those containing acid,anhydride, hydroxy, epoxy, and amine groups. Examples of usefulfunctional comonomers include, but are not limited to:N,N-dimethylaminoethyl(meth)acrylate, N,N-diethylaminoethyl(meth)acrylate, (meth)acrylamide, N,N-dimethylacrylamide,N-methylolacrylamide, N-methylaminopropyl(meth)acrylamide,N,N-dimethylaminopropyl(meth)acrylamide, N-ethylaminopropyl(meth)acrylamide, N,N-diethylaminopropyl (meth)acrylamide,N-methylacrylamide or N-t-butylacrylamide or N-ethyl (meth)acrylamide orchlorides of these compounds, 2-hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, 4-hydroxybutyl (meth)acrylate,glycidyl(meth)acrylate, ethyl alpha-hydroxymethacrylate, and2,3-dihydroxypropyl(meth)acrylate, maleic anhydride, maleic acid,substituted maleic anhydride, mono-ester of maleic anhydride, itaconicanhydride, itaconic acid, substituted itaconic anhydride, glutaricanhydride, monoester of itaconic acid, fumaric acid, fumaric anhydride,fumaric acid, substituted fumaric anhydride, monoester of fumaric acid,crotonic acid and its derivatives, acrylic acid, and methacrylic acid;cyanoalkoxyalkyl (meth)acrylates such as omega-cyanoethoxyethylacrylate, or omega-cyanoethoxyethyl methacrylate; vinyl monomerscontaining an aromatic ring and an hydroxyl group, such as vinylphenol,para-vinylbenzyl alcohol, meta-vinylphenethyl alcohol, vinylpyrrolidone, and vinyl imidazole; and other functional monomers, allylcellosolve, allyl carbinol, methylvinyl carbinol, allyl alcohol,methyllyl alcohol, glycidyl methacrylate, 3,4-epoxybutyl acrylate,acrylonitrile, methacrylonitrile, beta-cyanoethyl methacrylate,beta-cyanoethyl acrylate, Examples of polymerizable surfactants ormacromonomers with hydrophilic moieties useful in the present inventioninclude, but are not limited to sodium 1-allyloxy-2-hydroxypropanesulfonate, phosphate methacrylate monomer, poly(ethyleneglycol)methylether methacrylate, 1-methacrylamido, 2-imidazolidinoneethane. A preferred functionality for a PC/PET alloy isglycidyl(meth)acrylate.

The shell of the invention makes up less than 50 weight percent of thecore-shell polymer, preferably less than 30 weight percent and mostpreferably from 5 to 25 weight percent of the core-shell polymer.

The core/shell polymer of the invention is synthesized by emulsionfree-radical polymerization. A general procedure for producing a singlecore/single shell polymer particle will be described. One of skill inthe art will be able to modify this procedure to form other multi-layerparticles useful as impact modifiers. In a first stage, an emulsion isprepared which contains, per part by weight of monomers to bepolymerized, 1 to 10 parts of water, 0.001 to 0.03 parts of anemulsifying agent, a major portion of the elastomeric monomer mixtureand at least one polyfunctional crosslinking agent. The reaction mixturethus formed is stirred and maintained at a temperature ranging from 45°C. to 65° C. and preferably at a temperature in the region of 60° C.0.001 to 0.5 parts of a catalyst which generates free radicals is thenadded and the reaction mixture thus formed is maintained at atemperature of, for example, between ambient temperature and 100° C. andwith stirring for a period sufficient to obtain a virtually completeconversion of the monomers. The minor portion of elastomeric monomer(s)and the grafting agent, as well as, at the same time, 0.001 to 0.005part of a catalyst which generates free radicals, are then addedsimultaneously to the phase thus obtained.

In a second stage, the core is grafted with a monomer mixture containingat least one functional monomer. To do this, an appropriate amount ofthe said monomer mixture is added to the reaction mixture resulting fromthe first stage, in order to obtain a grafted copolymer containing thedesired content of grafted chains, as well as, if appropriate,additional amounts of emulsifying agent and of a radical catalyst alsowithin the ranges defined above, and the mixture thus formed ismaintained at a temperature within the abovementioned range, withstirring, until virtually complete conversion of the grafting monomersis obtained. Use may be made, as emulsifying agent, of any one of theknown surface-active agents, whether anionic, nonionic or even cationic.In particular, the emulsifying agent may be chosen from anionicemulsifying agents, such as sodium or potassium salts of fatty acids, inparticular sodium laurate, sodium stearate, sodium palmitate, sodiumoleate, mixed sulphates of sodium or of potassium and of fatty alcohols,in particular sodium lauryl sulphate, sodium or potassium salts ofsulphosuccinic esters, sodium or potassium salts of alkylarylsulphonicacids, in particular sodium dodecylbenzenesulphonate, and sodium orpotassium salts of fatty monoglyceride monosulphonates, or alternativelyfrom nonionic surfactants, such as the reaction products of ethyleneoxide and of alkylphenol or of aliphatic alcohols, alkylphenols. Use mayalso be made of mixtures of such surface-active agents, if need be.

In one embodiment, the emulsion may be made in a semi-continuousprocess, preferably at reaction temperatures of from 40-90° C., andpreferably from 45° C. to 65° C.

The catalysts capable of being employed, both in the abovementionedfirst emulsion polymerization stage and in the abovementioned secondemulsion polymerization stage, are compounds which give rise to freeradicals under the temperature conditions chosen for the polymerization.These compounds can in particular be peroxide compounds, such ashydrogen peroxide; alkali metal persulfates and in particular sodium orpotassium persulfate; ammonium persulfate; percarbonates; peracetates,perborates; peroxides such as benzoyl peroxide or lauroyl peroxide; orhydroperoxides such as cumene hydroperoxide, diisopropylbenzenehydroperoxide, para-menthane hydroperoxide or tert-butyl hydroperoxide.However, it is preferable to use catalytic systems of redox type formedby the combination of a peroxide compound, for example as mentionedabove, with a reducing agent, in particular such as alkali metalsulfite, alkali metal bisulfite, sodium formaldehyde sulfoxylate(NaHSO₂HCHO), ascorbic acid, glucose, and in particular those of thesaid catalytic systems which are water-soluble, for example potassiumpersulfate/sodium metabisulfite or alternatively diisopropylbenzenehydroperoxide/sodium formaldehyde sulfoxylate.

It is also possible to add, to the polymerization mixture of one and/orother of the stages, chain-limiting compounds, and in particularmercaptans such as tert-dodecyl mercaptan, isobutyl mercaptan, n-octylmercaptan, n-dodecyl mercaptan or isooctyl mercaptopropionate, for thepurpose of controlling the molecular mass of the core and/or of thechains grafted onto the nucleus, or alternatively compounds such asphosphates, for the purpose of controlling the ionic strength of thepolymerization mixture.

The reaction mixture obtained on conclusion of the second emulsionpolymerization stage, which is composed of an aqueous emulsion of thepolymer according to the invention, is then treated in order to separatethe said polymer therefrom. To do this, it is possible, for example, tosubject the emulsion, according to the surfactant used, to a coagulatingtreatment by bringing into contact with a saline solution (CaCl₂ orAlCl₃) or a solution acidified with concentrated sulfuric acid and thento separate, by filtration, the solid product resulting from thecoagulating, the said solid product then being washed and dried to givea graft copolymer as a powder. It is also possible to recover thepolymer contained in the emulsion by using a spray-drying technique,drum drying, freeze-drying or other means known in the art. During theprocess, additives such as talc may be used to aid in processing thepowder. Hard particles may be used in conjunction with the core-shellparticles of the invention to further improve anti-blocking andprocessing properties.

The resulting additive exists in the form of a powder, the particle sizeof which can range from a few microns, for example 0.05 to 5 microns, to200 to 450 microns, the said particle size depending on the techniqueused to separate the graft copolymer from the emulsion polymerizationmixture.

A similar procedure is used to produce a multi-layer core-shell polymer,with an additional polymerization stage for each layer.

The functionalized core-shell impact modifier of the invention isespecially useful in a polymer matrix that is a blend of a functionalpolymer or resin, and at least one other non-functional component.

The functional polymer in the matrix is a polymer than can interact withthe functional shell on the impact modifier, to form an attraction thathelps associate the impact modifier with the functional polymer.Examples of functional polymers useful in the present invention include,but are not limited to polyethylene terephthlate (PET); polybutyleneterephthlate (PBT); glycol modified polyethylene terephthlate (PETG);thermosetting polyester; thermoplastic polyesters; thermoplasticco-polyesters; polyetheresteramides; polyamides such as nylon 11, 12, 6,and 6,6; and natural polymers such as carbohydrates, cellulose, andbiopolymers such as polylactic acid and polyhydroxy butyrate.

The non-functional components could be polymeric, non-polymeric, or amixture thereof. Engineering resins useful as non-functional resinsinclude, but are not limited to, alkyl (meth)acrylate polymers andcopolymers, acrylonitrile/butadiene/styrene terpolymers (ABS),acrylonitrile/styrene/acrylate copolymers, polycarbonates,methacrylate/butadiene/styrene copolymers, polystyrene,acrylonitrile/acrylate copolymers, acrylonitrile/methyl methacrylatecopolymers, polyolefins, poly(vinyl chloride), a homopolymer of avinylidene halide, and alloys thereof.

The non-functional components could also be non-polymeric, includingfillers such as pigments and glass beads.

The blend of nonfunctional to functional polymers is such that thenonfunctional polymer is present at from 20-80 wt percent, preferablyfrom 40-75 weight percent and more preferably at from 50-75 weightpercent, while said functional polymer is present at from 20-80 weightpercent, preferably from 25 to 60 weight percent and more preferably atfrom 50 to 75 weight percent, based on the weight of the functional andnon-functional polymers (not including the MBS impact modifier or otheradditives).

The functional core-shell impact modifier of the invention is blendedinto the polymeric composition at a level of from 0.5 to 70 percent byweight, and preferably 2 to 55 percent by weight, based on the weight ofthe polymers. The impact modified may be blended into the plastic bystandard means such as melt extrusion, compaction, roll mill, and othersuch means as known in the art.

In addition to the polymers and the impact modifier, one or more otheradditives may also be added at usual levels. Typical additives include,but are not limited to, processing aids, anti-oxidants, stabilizers,pigments, dyes, plasticizers, antioxidants, or lubricants.

The impact modified thermoplastic composition according to the inventioncan be prepared by any method which makes it possible to produce ahomogeneous mixture containing a thermoplastic polymer, the impactadditive according to the invention and optionally other additives. Itis possible, for example, to dry-mix the ingredients constituting theresin composition, then to extrude the resulting mixture and to reducethe extrudate to pellets. When the thermoplastic polymer is obtained byemulsion polymerization, it may be convenient to mix the emulsioncontaining the core-shell additive according to the invention with theemulsion of the thermoplastic polymer and to treat the resultingemulsion in order to separate therefrom the solid product which itcontains, as described above with respect to the separation of thecore-shell polymer.

In one embodiment of the invention, the functionalized core-shellpolymer is used in an engineering resin/PET blend. In a preferredembodiment the functionalized core-shell modifier is used in a PC/PETblend, providing an impact modification at −30° F. of at least 28 kJ/m².

Some specific examples of the compositions of the invention are listedbelow. Those in the art would e able to recognize other examples of theinvention, based on the specification and examples listed:

-   -   The functional core shell polymer and a blend of polycarbonate        (20 to 80 wt %) and PET (20-80 wt % based on weight of total        polymer solids).    -   The functional core shell polymer and a glass fiber reinforced        polyamide.    -   The functional core shell polymer and a blend of a natural or        biopolymer and a methyl(meth)acrylate homopolymer or copolymer.

The following examples are intended to illustrate further variousaspects of the present invention, but are not intended to limit thescope of the invention in any aspect.

EXAMPLES Example 1 Functionalized Core-Shell Impact Modifier

Core:

To a 1-gallon high-pressure reactor was charged: de-ionized water,emulsifier, 1,3-butadiene, t-dodecyl mercaptan, and p-menthanehydroperoxide as an initial kettle charge, as outlined below. Thesolution was heated, with agitation, to 43° C. at which time aredox-based catalyst solution was charged, effectively initiating thepolymerization. Then the solution was further heated to 56° C. and heldat this temperature for a period of three hours.

Three hours after polymerization initiation, a second monomer charge,one-half of an additional emulsifier and reductant charge, andadditional initiator were continuously added over eight hours. Followthe completion of the second monomer addition, the remaining emulsifierand reductant charge plus initiator was continuously added over anadditional five hours.

Thirteen hours after polymerization initiation, the solution was heatedto 68° C. and allowed to react until at least twenty hours had elapsedsince polymerization initiation, producing butadiene rubber latex, R₁.

The resultant butadiene rubber latex (R₁) contained 38% solids and had aparticle size, d_(w), of ≈160 nm and a d_(w)/d_(n) of 1.1.

Butadiene Rubber Latex, R₁ Kettle Charge de-ionized water 116.5 partsbeef tallow fatty acid, potassium salt 0.1 parts 1,3-butadiene 21.9parts t-dodecyl mercaptan 0.1 parts Initiator p-menthane hydroperoxide0.1 parts Redox-based Catalyst de-ionized water 4.5 parts sodiumtetrapyrophosphate 0.3 parts ferrous sulfate 0.004 parts dextrose 0.3parts Second Monomer 1,3-butadiene 77.8 parts t-dodecyl mercaptan 0.2parts Emulsifier & Reductant de-ionized water 30.4 parts beef tallowfatty acid, potassium salt 2.8 parts dextrose 0.5 parts Initiatorp-menthane hydroperoxide 0.8 partsGraft Polymerization:

A 5-liter reactor was charged with de-ionized water and polybutadienerubber latex. The reactor was assembled inside the hood on a heatingmantle and was purged with nitrogen for 20 minutes while heating it to77° C. at 180 rpm.

At 55° C., a pre-mixed solution of hydroxymethane sulfinic acid, sodiumsalt (CRO) in de-ionized water was added via syringe.

A premixed solution of a mixture of monomers methyl methacrylate(85-99.0 weight percent), ethyl acrylate (0-5 weight percent), glycidylmethacrylate (0.5 to 10 wt percent), along with divinyl benzene (chaintransfer agent) (0.5-6 wt. percent) (the total equaling 100 weightpercent), and t-butyl hydroperoxide (initiator) was added to the reactorfor over 70 minutes in a semi-continuous feeding.

After the end of addition of shell monomers, the reaction was kept onhold for 80 minutes.

At 30 minutes hold, an aliquot of initiator, hydroxymethane sulfinicacid, sodium salt (CRO), and t-butyl hydroperoxide (CHT) in de-ionizedwater, was added to facilitate the conversion of un-reacted monomers, ifany.

After 80 minutes of holding period is complete, anti-oxidant package wasadded to the reactor and the reaction was allowed to cool to roomtemperature. [Anti-oxidant emulsion was made by heating a mixture ofTriethyleneglycol-bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionate),Dilauryl Thiodipropionate, and Oleic acid followed by addition of asolution of potassium hydroxide in de-ionized water]

The grafted latex was then filtered through a cheese-cloth into a1-gallon bottle.

Coagulation

A 5-liter reactor was charged with de-ionized water and concentratedsulfuric acid. The reactor was assembled in the hood on a heating mantleand the temperature was raised to 51.7° C. at 180 rpm. At 51.7° C., thegrafted latex (above) was added slowly while increasing the agitation to400 rpm. The latex instantly coagulated. After the completion ofaddition of grafted latex, the reaction mixture was rinsed withde-ionized water. Then, flow aid latex (P550) was added to the reactorslowly.

The coagulation reaction was kept on hold at 51.7° C. for 20 minutesconstantly stirring at about 400 rpm. After 20 minutes, reactor washeated to 85° C. During this heating a sample was pulled out from thereactor via syringe and its pH was measured.

The pH was adjusted to 3.5 by adding a 20% solution by weight ofpotassium.

Once, the pH is reached, hold the reaction at 85° C. for 20 minutes.After 20 minutes holding in complete, the reaction temperature wasraised to 96.1° C. and kept on hold at this temperature for 20 moreminutes. The hot coagulated polymer was vacuum filtered and washed withhot water (>50° C.). The white polymer powder was dried in vacuum for 2hours and dried in oven at 120° C. overnight.

Example 2

A comparison of the effect of the functional impact modifiers of theinvention on PC/PBT and PC/PET alloys was conducted. In each experimentthe PC alloy contained 50 weight percent of PC, and 50 weight percent ofPBT or PET. The MBS is a 78% butadiene core/12% shell, with the shellcontaining 10 weight percent glycidyl methacrylate and 90 weight percentMMA. The low temperature impact was measured by ASTM D256. The resultsare found in TABLE 1.

TABLE 1 −20° C. −30° C. PC/PBT  6.3 kJ/m²  4.8 kJ/m² 12% MBS 26.3 kJ/m²25.2 kJ/m² PC/PET  6.0 kJ/m²  6.1 kJ/m² 12% MBS 46.1 kJ/m² 40.4 kJ/m²

The results show that the improvement in low temperature impact strengthfor the PC/PET alloy is much higher than that for the PC/PBT alloy.While not being bound by any particular theory, it is believed that thedifference is likely associated with the variations in crystallizationrates between the two resins.

What is claimed is:
 1. An impact modified polymer alloy compositionconsisting of: a) one or more functional polymers selected from thegroup consisting of polyethylene terephthlate (PET), polyamides, glycolmodified polyethylene terephthlate (PETG), natural polymers,carbohydrates, cellulose, biopolymers, polylactic acid, and polyhydroxybutyrate, b) one or more non-functional polymers selected from the groupconsisting of alkyl (meth)acrylate polymers and copolymers,acrylonitrile/butadiene/styrene terpolymers (ABS),acrylonitrile/styrene/acrylate copolymers, polycarbonates,methacrylate/butadiene/styrene copolymers, polystyrene,acrylonitrile/acrylate copolymers, acrylonitrile/methyl methacrylatecopolymers, poly(vinyl chloride), a homopolymer of a vinylidene halide,and alloys thereof; wherein the ratio of functional polymer tonon-functional polymer is from 20:80 to 80:20, and c) functionalcore-shell impact modifier, wherein the outer-most shell comprises from0.5 to 30 weight percent, based on the shell polymer, of functionalgroups including at least glycidyl(meth)acrylate, and the core comprisesone or more polymers selected from the group consisting ofstyrene-butadiene, butadiene, and methacrylate-butadiene-styrene, andoptionally d) non-functional additives selected from the groupconsisting of glass beads, polymer beads, glass fibers, carbonnanotubes, and pigments.
 2. The impact modified composition of claim 1,wherein said core-shell polymer has a styrene-butadiene core.
 3. Theimpact modified composition of claim 1, wherein said core-shell polymerhas a butadiene homopolymer core.
 4. The impact modified composition ofclaim 1, wherein said core-shell polymer has an outermost shell furthercomprising methyl(meth)acrylate.
 5. The impact modified composition ofclaim 1, wherein said functional polymer is polyethylene terephthlate,polyamides, or glycol modified polyethylene terephthlate (PETG).
 6. Theimpact modified composition of claim 1, wherein said non-functionalpolymer comprises polycarbonate, or polymethyl(meth)acrylatehomopolymers and copolymers.
 7. The impact modified composition of claim1, wherein said functional core-shell impact modifier comprises from 0.5to 70 wt % of the polymer alloy composition.
 8. The impact modifiedcomposition of claim 1, wherein said functional core-shell impactmodifier comprises from 2 to 55 wt % of the polymer alloy composition.9. The impact modified composition of claim 1, wherein the outer shellof said functional core-shell impact comprises from 1-20 weight percentof functional groups.
 10. The impact modified composition of claim 1,wherein the ratio of functional polymer to non-functional polymer isfrom 40:60 to 75:25.
 11. The impact modified composition of claim 1,wherein the functional polymer is PET, the non-functional polymer ispolycarbonate.